Showing 10 results for Emam Jomeh
Volume 12, Issue 49 (10-2015)
Abstract
This study investigates the effect of olive oil on the caseinate‐based films. Edible films based on caseinate (5% (w/v)) and glycerol (30% (w/w)) by varying olive oil concentrations (0, 10, 20 and 30% (w/w), were prepared by casting method films. The impact of the incorporation of olive oil into the film matrix was studied by investigating the physical and mechanical properties of films. Scanning electron microscopy (SEM) was also used in order to analyse films microstructure. Increasing the olive oil concentrationup to30%(w/w) decreased values for thickness and solubility from 0.050mm and 92.18% to 0.042mm and 61.84% respectively and caused the films to become opaque. Also addition of olive oil to caseinate emulsion significantly improved the WVP (upto9×10-10g/s.m.pa)of prepared films, but lowered the mechanical properties. The results indicate that the structure and properties of caseinate edible films were modified and improved by the olive oil.
Volume 12, Issue 49 (10-2015)
Abstract
In present study, dried pomegranate peel of three dominant Iranian varieties was extracted by soxhlet extraction (SE) method via four solvents. In this study Five anthocyanins were identified and quantified in the extracts by high performance liquid chromatography (HPLC) coupled with ultraviolet-visible (UV-Vis) spectrometric detector at wavelength of 517 nm according to their retention times and external standard method. According to the results extraction yield of Poost Siyahe Shirine Ardestan (PSSA) variety is more than other two varieties and extraction yield of ethanolic extracts is more than other solvents in p≤0.05. HPLC analysis was indicated pomegranate peel include of more mono glucoside anthocyanins than di glucoside anthocyanins also the most of anthocyanins particularly mono glucoside anthocyanins were detected in ethanolic extract obtained from dried peel of PSSA variety.
Volume 13, Issue 50 (5-2016)
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Volume 13, Issue 50 (5-2016)
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Volume 13, Issue 50 (5-2016)
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Volume 13, Issue 51 (7-2016)
Abstract
Salep composite films containing 0±30% (w/w) oleic acid or stearic acid – were prepared through emulsification and their physical, mechanical, and barrier properties were evaluated and compared. Emulsified films were softer than pure films. Addition of the fatty acids to salep films significantly improved the WVP (P<0.05), but lowered the tensile strength. Stearic acid was more effective than oleic acid in reducing the WVP, but films with oleic acid showed better mechanical properties overall than those with stearic acid . Also the presence of fatty acids decreased solubility in water and caused the films to become opaque. On the other, fatty acids showed different effects on the elongation at break. This work showed that when taking all the studied variables into account, films formulated with oleic acid were found most suitable for various food applications.
Volume 13, Issue 56 (10-2015)
Abstract
In order to increase the shelf life, improve availability and reduce the storage and transportation costs, our study aimed at concentrating of two kinds of juices obtained from two raspberry cultivars (modified black and wild red) by two new techniques of vacuum and microwave in three pressure levels 12, 38/5 and 100 kPa. The influence of concentration process and operational parameters (concentrating duration and pressure) on color factors (a*, b* and L*) and antioxidant activity of the final product were assessed. Considering that the samples color is influenced by the presence of anthocyanins, relationship between color and antioxidant activity were determined by a high coefficient of determination (R2= 1). Results suggest color and anthocyanins deteriorate over time. Deterioration rate depends on the kind of concentration process and process pressure, being higher in evaporator-rotary technique and atmospheric pressure. Moreover, anthocyanin half-life times in the pressures 100, 38.5 and 12 kPa were 93.7, 97.7 and 103 min in evaporator-rotary technique and 146.5, 233 and 480 min in microwave technique for modified black raspberry, respectively while being 93.5, 115.5 and 117 min in evaporator-rotary and 118, 480 and 515 min in microwave technique for wild red raspberry, respectively.
Volume 13, Issue 57 (0-0)
Abstract
Abstract: Raspberry is a good source in terms of antocianines, polyphenols, vitamin C, fibers, proteins and minerals contents. Raspberry juice is susceptible to enzymatic and microbial reactions, because of its high moisture content (75-90%). Concentration of Raspberry juice increases its shelf life, while decreasing costs of storage and transport. In this study, extracts obtained from two raspberry cultivars of Amol (red) and Siyahkal (black) were concentrated by two methods, radiation (microwave) and convention (evaporator-rotary) applying three pressure levels: 12, 38.5 and 100 kPa. Changes in physicochemical properties including brix, acidity, pH, turbidity and color were assessed during the concentration process of two kinds of juice. Results showed decrease in acidity and color and increase in brix and turbidity of the juices, but rate and amount of changes were dissimilar in different methods and pressures. Samples concentrated by radiation using microwave in comparison with conventional method (evaporator-rotary) had superior quality. Furthermore, decrease in pressure led to better quality in product in both techniques.
Volume 13, Issue 58 (0-0)
Abstract
The objective of this research was to investigate the feasibility of edible film made from salep in which the hydrophobicity of film was modified by using stearic acid as a lipid agent. In addition its mechanical, thermal, permeability and color changes of film were analyzed. For this purpose, edible composite films were prepared from salep, stearic acid, and tween 80 in emulsion form using an ultra turax apparatus. The water vapor permeability (WVP) of the emulsified films was reduced by fatty acid addition. Also the permeability to oxygen of the emulsified films was lower than that of a salep film without fatty acid, but the difference was not significant in higher concentration of stearic acid. Scanning electron microscopy (SEM) was also used in order to analyze films microstructure. Finally, differential scanning calorimetry showed that the glass transition temperature (Tg) of the salep film was 12 °C and was considerably affected by stearic acid concentration.
Volume 13, Issue 60 (0-0)
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